fix: strip trailing spaces and NULs when setting environment variables from COBOL

libcobj/app/src/main/java/jp/osscons/opensourcecobol/libcobj/common/CobolUtil.java

@@ -632,10 +632,16 @@ public static void setEnv(String envVarName, String envVarValue) {
      *
      * @param envVarName the name of an environment variable. The leading and trailing spaces are
      *     ignored.
-     * @param envVarValue the value of an environment variable to be set.
+     * @param envVarValue the value of an environment variable to be set. Trailing spaces and NUL
+     *     bytes are stripped to match libcob's {@code cob_field_to_string} behavior.
      */
     public static void setEnv(AbstractCobolField envVarName, AbstractCobolField envVarValue) {
-        CobolUtil.envVarTable.setProperty(envVarName.getString().trim(), envVarValue.getString());
+        // Name side uses String#trim() to drop both leading and trailing spaces, matching the
+        // behavior documented above. Value side uses fieldToString so only trailing spaces/NULs
+        // are stripped (leading spaces are meaningful in an environment value).
+        CobolUtil.envVarTable.setProperty(
+                envVarName.getString().trim(),
+                envVarValue.fieldToString(AbstractCobolField.charSetSJIS));
     }
 
     /**

libcobj/app/src/main/java/jp/osscons/opensourcecobol/libcobj/data/AbstractCobolField.java

@@ -1024,6 +1024,25 @@ public String fieldToString() {
         return new String(data.getByteArray(0, i + 1));
     }
 
+    /**
+     * 末尾の空白とNULバイトを取り除いたうえで指定されたcharsetでデコードして文字列として返す.
+     * 本家CのopensourceCOBOLにおける{@code cob_field_to_string}と同等の処理を行う.
+     *
+     * @param charset デコードに使用するcharset
+     * @return 末尾の空白/NULを取り除いた文字列
+     */
+    public String fieldToString(Charset charset) {
+        CobolDataStorage data = this.getDataStorage();
+        int end;
+        for (end = this.getSize(); end > 0; --end) {
+            byte b = data.getByte(end - 1);
+            if (b != ' ' && b != 0) {
+                break;
+            }
+        }
+        return new String(data.getByteArray(0, end), charset);
+    }
+
     /**
      * TODO: 準備中
      *

libcobj/app/src/main/java/jp/osscons/opensourcecobol/libcobj/termio/CobolTerminal.java

@@ -252,14 +252,21 @@ public static void displayEnvironment(AbstractCobolField f) {
      * で設定された環境変数名に対して値を設定する. 環境変数名が未設定または空文字列の場合は{@link
      * CobolExceptionId#COB_EC_IMP_DISPLAY}例外を設定する.
      *
+     * <p>COBOL変数{@code f}の値は{@link AbstractCobolField#fieldToString(java.nio.charset.Charset)}
+     * によって末尾の空白とNULバイトが取り除かれてから環境変数値として設定される. これは本家CのopensourceCOBOLが
+     * {@code cob_display_env_value}内で{@code cob_field_to_string}を使用する挙動と一致する.
+     *
      * @param f 設定する環境変数の値を保持するCOBOL変数
      */
     public static void displayEnvValue(AbstractCobolField f) {
         if (CobolUtil.cobLocalEnv == null || CobolUtil.cobLocalEnv.equals("")) {
             CobolExceptionInfo.setException(CobolExceptionId.COB_EC_IMP_DISPLAY);
             return;
         }
-        CobolUtil.setEnv(CobolUtil.cobLocalEnv, f.getString());
+        // Strip trailing spaces and NULs so that PIC X(n) source fields do not
+        // leak padding into the environment variable value. Matches libcob's
+        // cob_field_to_string used by cob_display_env_value.
+        CobolUtil.setEnv(CobolUtil.cobLocalEnv, f.fieldToString(AbstractCobolField.charSetSJIS));
     }
 
     /**

tests/jp-compat.src/special-names.at

@@ -145,6 +145,77 @@ AT_CHECK([export TESTENV=envvalue && java prog], [0], [envvalue:newvalue])
 
 AT_CLEANUP
 
+AT_SETUP([DISPLAY ENVIRONMENT-VALUE strips trailing spaces])
+
+AT_DATA([prog.cob], [
+       IDENTIFICATION   DIVISION.
+       PROGRAM-ID.      prog.
+       ENVIRONMENT      DIVISION.
+       INPUT-OUTPUT     SECTION.
+       FILE-CONTROL.
+           SELECT OUT-FILE ASSIGN OUTPATH
+                  ORGANIZATION IS LINE SEQUENTIAL.
+       DATA             DIVISION.
+       FILE             SECTION.
+       FD OUT-FILE.
+       01 OUT-REC       PIC X(5).
+       WORKING-STORAGE  SECTION.
+       01 WK-PATH       PIC X(32).
+       PROCEDURE        DIVISION.
+           MOVE SPACE         TO WK-PATH.
+           STRING 'hello.txt' DELIMITED BY SIZE
+                  INTO WK-PATH.
+           DISPLAY 'OUTPATH'  UPON ENVIRONMENT-NAME.
+           DISPLAY WK-PATH    UPON ENVIRONMENT-VALUE.
+           OPEN OUTPUT OUT-FILE.
+           MOVE 'HELLO'       TO OUT-REC.
+           WRITE OUT-REC.
+           CLOSE OUT-FILE.
+           STOP RUN.
+])
+
+AT_CHECK([${COMPILE_JP_COMPAT} prog.cob], [0])
+AT_CHECK([java prog], [0])
+AT_CHECK([test -f hello.txt && cat hello.txt], [0], [HELLO
+])
+
+AT_CLEANUP
+
+AT_SETUP([SET ENVIRONMENT strips trailing spaces])
+
+AT_DATA([prog.cob], [
+       IDENTIFICATION   DIVISION.
+       PROGRAM-ID.      prog.
+       ENVIRONMENT      DIVISION.
+       INPUT-OUTPUT     SECTION.
+       FILE-CONTROL.
+           SELECT OUT-FILE ASSIGN OUTPATH2
+                  ORGANIZATION IS LINE SEQUENTIAL.
+       DATA             DIVISION.
+       FILE             SECTION.
+       FD OUT-FILE.
+       01 OUT-REC       PIC X(5).
+       WORKING-STORAGE  SECTION.
+       01 WK-PATH       PIC X(32).
+       PROCEDURE        DIVISION.
+           MOVE SPACE         TO WK-PATH.
+           STRING 'world.txt' DELIMITED BY SIZE
+                  INTO WK-PATH.
+           SET ENVIRONMENT 'OUTPATH2' TO WK-PATH.
+           OPEN OUTPUT OUT-FILE.
+           MOVE 'WORLD'       TO OUT-REC.
+           WRITE OUT-REC.
+           CLOSE OUT-FILE.
+           STOP RUN.
+])
+
+AT_CHECK([${COMPILE_JP_COMPAT} prog.cob], [0])
+AT_CHECK([java prog], [0])
+AT_CHECK([test -f world.txt && cat world.txt], [0], [WORLD
+])
+
+AT_CLEANUP
+
 AT_SETUP([SPECIAL NAMES unterminated])
 
 AT_DATA([prog.cob], [